Varlable condenser



March 26, 1935. s. COHEN Y VARIABLE CONDENSER 4 Sheets-Sheet l Filed Feb. 2, 1932 INVENTOR.

ATTORNEY 6AM/mmf @o March 26, 1935. s. COHEN VARIABLE CONDENSER Filed Feb. 2, 1932 4 Sheets-Sheet 2 2 In JT i;

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A TTORNEY March Z6, 1935. s. COHEN VARIABLE coNDENsER Filed Feb. 2, 1932 4 Sheets-Sheet 3 March 26, 1935. I s, COHEN 1,995,669

VARIABLE CONDENSER Filed Feb. 2, 1932 4 Sheets-Sheet 4 IN VEN TOR.

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BY i e ATTORNEY ilatented lil/1an 26?, i935 UITED STATES PAT NT ossioe ei'ai Instrument Corporation, New York, N. Yn2 a corporation of New York Application February 2, 1932, Set'iai Non 5995488 i Claims.

My invention relates broadly to variable elec-J trical condensers and more particularly to an improved construction of a multiple variable condenser.

One of the objects of my invention is to profvide s. simplified construction of multiple unit variable condenser which is capable of quantity production at low cost and adapted for simplied assembly processes.

Another object of my invention is to provide a simplied construction of multiple unit variable condenser wherein sets of stator plates may be mounted within a condenser frame by supporting the stator plates on downwardly depending insulated members suspended from strip members supported by the condenser frame.

Still another object of my invention to provide a siinplied method of assembly for the stator plates of a multiple unit variable condenser wherein the sets of stator plates may be insulatingly mounted in Jnredetermined spaced relation as independent units from longitudinally extendm ing strip members supported by tire condenser frame.

A still further object of my invention is to provide a construction of multiple variable condenser in which the stator units are suspended laterally of a condenser chassis between two longitndinnily extending strip members supported by the end plates and lateraily extending intermediate shield plates ci t'ne multioie variable condenser chassis.

Otner and further objects of my invention reside the method of assembly and construction of multiple variable condensers as torto more fully the specication hereinafter following by reference to the accompanying in which:

i is a top plan view of a condenser con structed in @accordance with my invention; 2 is ont elevation thereof; Fig. El similar' view opposite side; fi, 5 aid 6 'Hansi/"ered tical, sectionai views rf taken coi i; i and il are fragment 97s 'taken e 2; Q is a la iizontal @me of l5; l vertical sectionai shoving the io stator plates e view t?.

(Ci. 17d-4225) Fig. i3 is a perspective vien:r of the series of transversely extending plates constituting part of my improved condenser; Fig. lll is a perspective View of the' base plate; end l5 is e peru speotive View of the pair ci longitudinally tending strips forming part of my improved oondenser.

Referring to the drawings in. detail, reference character l designates the lower portion of the pressed metal frame of the multiple variable condenser having opstanding side walls 2. The upstanding side Walls 2 each llave lugs 2a on opposite ends thereof. The lower portion or" the frame l 'nas horizontally projecting 'lugs 2b formed thereon. End plates 3 are secured to the ends of the lower portion of tures 3e and 3b being formed in the end plates 3 to permit the passage of the lugs 2a, and 2b, respectively. The lugs 2a and when passed through the apertures 3a and Bln in the iid plates 3 are sweged over for rigidly securing ine end plates in erect position with respect to lower portion oi the condenser frame at i. Tile lower portion oi tile condenser ira; is provided with stamped outouts Sic and bosses lo". Suitable securing means may through the bosses ld for anchoring the condenser chassis in position with respect to title frame of a broadcast radio receiver with which the condenser is adapted to be associated. The condenser extend laterally of tile condenser :l and con? se oi stato plates l@ an' ating ro or plates l. 'When assemble ts feter and rotor plates are elec-tio Licaly shielded .from eacli other by ineens oi intermediate plates 4, ilntel'l'oediate plates i are provided with sidecut out 'n ions ec with goes or lugs projecting thereon. 'i'lie lowerrpo tli plates el is provided lugs i* e shield 1o vertice entendis be freine l, aper-f to be aligned wil @lates ilirougl'f. is arranged to pair ci loif'itndii therein through which rivet members 7, connected with depending insulated members 6, are secured. The insulated depending members 6 are suspended from `the longitudinally extending strips and. provide mounting means for the stator plate units. Each of the stator plate units consists of aplurality of plates having lugs 10a and 10b formed thereon and engaged by `the members 3 which provide rigid supports for the stator plates 10. Themembers 8 have channel- Ways extending therethrough normal to the planes of the stator plates 10 and through these channelways there extends tie bars 11 which are screw threaded to receive screws 9 which extend through apertures 9a. in insulated members 6, through the sheet metal of member 8, and into the screw threads in tie bars 11. In order to clearly illustrate-the invention I have in Figs. l, 7 and 8 shown the stator units with one end plate removed thereby showing the arrangement of the apertures 8a and 8b in members 8 through which thelugs 10a. and 10b of the stator plates are arranged to pass. After the stator units areassembled in predetermined spaced relation depending from the longitudinally extending strips 5 and supported by the intermediate shield plates 4 with the lugs or tongues 4d swaged over, the

condenser frame is prepared to receive the end plates 3. TheY end plates 3 are then moved toward each end of the condenser chassis so that the tongues 2a and 2b on the lower portion 1 of the condenser frame and the lugs 5c on the longitudinally extending strips 5 are aligned with and passed through the apertures 3a, 3b and 3c in the end plates 3. Thereafter, the lugs 2a, 2l) and 5c are swaged over for establishing a rigid connection between the longitudinally extending strips 5, the end plates 3 and the lower portion of the condenser frame 1.

It will be observed that in the assembly process the insulated members 6 are first riveted by means of rivets 7 to one of the longitudinally extending strips 5, the strip 5 being secured to the edges of vintermediate shield plates 4 by means of lugs 4d passing through apertures 5d in the 'aforementioned strip 5. The opposite strip 5 may then be applied `to the insulated members 6 on the other sides of theI stator units and connected to lthe opposite edges of the intermediate shield plates 4 by tongues 4d projecting through apertures 5d in the opposite strip 5. The stator units including the intermediate shield plates 4 may now be assembled into the condenser frame by lowering the shield plates 4 into position where slots 4a embrace the upstandixig side walls 2 of the lower'porti'on of the condenser frame 1, the

tongues 4b projecting through the apertures 2c in frame 1 and being fswaged over to rigidly connect the parts-of the condenser frame. The end plates 3 are now secured in position by moving the plates and the apertures 3a, 3b and 3c into registry with tongues 2a, 2b and 5c and swaging the tongues for securing' the frame in rigid position. The rotary shaft 12 is passed longitudinally through the apertures 12a and 12b in the end plates and the intermediate shield plates 4, respectively. Journals 12a in the end plates 3 house ball bearing races in which the rotary shaft 12 revolves. Plate member 12e closes the ball race formed in the end plate 3 shown at the left in Fig. 1 and permits rotation of shaft 12l while maintaining the rotor plates in proper position. Shaft 12 carries sleeve members 15 which are grooved to support the rotor plates 14 in spaced relation and adapted to be interleaved Lacasse j passes.

with the sets of stator plates 10. The rotor plates 14 are keyed at one edge thereof by means of a key strip 16 which fits into grooves formed in the edges of the rotor plates 14. 'I

Figure 11 shows a fragmentary view of the rotor plates provided with aligned grooves 17 oiset at 17a to receive the double T-shaped insulation member 18. member 18 has -the upper portion 18a thereof fitted within groove 17a, immediately behind key strip 16. The depending parts 18h of the double T-shaped strip extend between adjacent rotor plates 14 and provide a projecting strip engageable with the oiset edges 10c ofthe stator plates 10 when the condenser is movedto maximum4 vcapacity position, for preventing any short-cir- The rotor plates are xed on shaft 12 by means of setV cuit between the rotor and stator plates.

screws 19 which extend through the sleeves 15 and serve to anchor the rotor plates on the shaft 12. A suricient degree of friction is introduced at each of the condenser stages to permit precision adjustment of thevariable condenser to any selected position. For this purpose I employ spring members 20 engageable with the end plate 3 or intermediate shield plate 4 and bearing against the end of sleeve 1'5.

VAt one side of the condenser I provide trimmer condenser units supported by the insulated members 6. The trimmer condenser units are consti- The double T-shaped insulation.

tuted by resilient plate members 2l having a con- I necting lug 22 and being secured by means of screw members 9. Each plate member 21 has a resilient offset portion 24 to allow lateral adjustment of the plate 21 with respect to the strip 5 under control of set screw 25.A Set screw 25 is insulated from movable plate 21 bymeans of washer member 26 and by reason of the enlarged aperture in plate 21 through which screw 25 A sheet of mica or other insulated material 27 provides means for insulating adjustable plate 21 from strip member 5. Inasmuch as strip member 5 is grounded to the frame of the condenser and to the rotatable shaft 12 and rotor plates 14 carried'thereby, and in view of the fact that stator plates 10 are connected through member 8 and screws 9 with trimmer condenser plate 21, each trimmer condenser is thereby placed in shunt with the coordinated sets 'of stator and rotor plates so that an adjustment of maximum to minimum capacity ratio may be effected for each condenser stage. Each set of rotor plates is provided with an an end plate which is formed with radially extending slots which I have shown at 28 in Fig. 4. These slots extend less than onehalf the radius of the rotor plate and serve to divide the rotor plate into a plurality of segments cision operation.

I have found that the method of mounting the stator plates through the depending insulating members independent of the lower portion of the condenser frame, greatly facilitates and simplifles the manufacture of condensers. have described my invention in certain preferred kpermitted for adjusting the condenser for pre- While I embodiments I desire that it be understood that A modications may be made and that no limita- Y tions upon my invention are intended other than are imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

l. A multiple variable condenser comprising a channel shaped chassis, an end plate` secured at each end of said chassis, a pair of flat metallic strips extending between said end plates longitudinally of said chassis on opposite sides thereof and above the edge extremities of the walls of said channel shaped chassis, insulated plate members secured'at their upper ends to said strips, shield plates extending transversely of said chassis and having oppositely disposed recesses therein receiving said strips, tongues in said recesses engaged through said strips between the insulated plate members, stator units extending transversely of said chassis between the shield plates and end plates and consisting of spaced plates secured at .their ends to the insulated plate members and spaced from said chassis, a shaft journaled through said end plates, and rotor units carried by said shaft in position whereby plates of the rotor units may interleave with plates of companion stator units. Y

2. A multiple variable condenser comprising a supporting plate formed of sheet metal and having side portions bent to form upstanding flanges, said supporting plate having slots formed transversely therein adjacent said flanges and tongues provided at ends of the flanges and at ends of the plate adjacent the flanges, end plates, and intermediate plates, the end plates having slots to receive said tongues and firmly secure the end plates to the supporting plate and flanges thereof, and the intermediate plates having slots leading from their lower edges to receive said flanges, tongues extending from lower edges of the intermediate plates and engaged through the slots of the supporting plate to secure the intermediate plates thereto, independent metal strips extending from one end plate to the other above the edges of said flanges and in planes parallel thereto and having tongues at their ends engaged through other slots formed in the end plates, said strips being seated in recesses formed in ends of the intermediate plates and fonned with slots receiving tongues carried by the intermediate plates to secure the intermediate plates to the strips, insulating plates xed to said strips and depending therefrom between the end plates and intermediate plates; sets of stator plates extending between the intermediate platesl and end plates and Vhaving end brackets secured to the insulating plates to mount the stator plates in'l spacial relation to said supporting plate. and its flanges, a rotatable shaft journaled in said end plates and extendingl through aligned openings formed in the intermediate plates, and sets of rotor plates carried by said shaft to turn with the shaft and adapted to be interleaved with the plates of companion sets of stator plates.

3. A multiple variable condenser comprising a supporting plate formed of sheet metal and having side portions bent to form upstanding anges, said supporting plate having slots formed transversely therein adjacent said flanges, and tongues provided at ends of the flanges and at ends of the plate adjacent the anges, end plates and intermediate plates, the end plates having slots to receive said tongues and llrmly secure the end plates to the supporting plate and flanges thereof, and theintermediate plates being slotted to embrace said flanges and abut with said supporting plate between said flanges, said intermediate plates having oppositely disposed recesses in the opposite edges thereof, tongues projecting from said intermediate plates within said recesses, independent metallic strip members seated in said recesses in planes offset outwardly from said flanges 'in planes substantiallyparallel thereto, said strip members having apertures engaged by said tongues, sets of stator plates insulatingly supported by said strip members between said end plates and said intermediate plates, a rotor shaft and sets of rotor plates carried by said shaft and adapted to be variably interleaved with said stator plates.

4. In a multiple variable condenser, a shallow channel shaped frame havingA upwardly extending side flanges, an assembly comprising a pair of independent flat strips extending longitudinally of said frame, insulated plates carried by said strips and depending therefrom at spaced intervals along the length thereof, said strips being disposed in planes offset from the planes of said flanges by distances substantially `equal to the thickness of said insulated plates, electrostatic shields extending between said strips with their ends secured thereto intermediate the connection of said insulated plates therewith, stator plate units suspended between said insulated plates, end platessecured to the ends of said strips and to the ends of said channel shaped frame, a shaft journaled in said end plates and extending through the electrostatic shields, and rotor plates carried by said shaft and adapted to be interleaved with said stator plates.

' SAMUEL COHEN. 

